In a mixing bowl, combine yogurt, tomato paste, ginger-garlic paste, salt, all spices, lemon juice, and chopped coriander.
Mix well until it forms a smooth marinade.
In a large bowl, add the chicken drumsticks and cubed potatoes.
Pour the prepared marinade over them and mix thoroughly to coat everything evenly.
Let it marinate for 1-2 hours for best flavor, or cook immediately if short on time.
Heat a large, wide pan over medium heat and add oil.
Add the marinated chicken and potatoes to the pan, reserving any leftover marinade.
Cook for 5-6 minutes, stirring occasionally.
Stir again and continue cooking for another 4-5 minutes to develop color on the chicken.
Pour the remaining marinade into the pan and mix well.
Cover the pan and reduce heat to low, letting it cook for 25-30 minutes until the chicken is tender and the potatoes are soft.
Garnish with fresh coriander.
Serve hot with steamed rice, chapati, or naan.